Question

我的群集大小是6台机器，我经常收到此错误消息，而且我真的不知道如何解决这个问题：

code=1100 [Coordinator node timed out waiting for replica nodes' responses] message="Operation timed out - received only 0 responses." info={'received_responses': 0, 'required_responses': 1, 'consistency': 'LOCAL_ONE'}

这是我的完整代码，并且出现错误消息的代码部分是：

batch.add(schedule_remove_stmt, (source, type, row['scheduled_for'],row['id']));session.execute(batch,30)

完整代码：

cluster = Cluster(['localhost'])
session = cluster.connect('keyspace')
d = datetime.utcnow()
scheduled_for = d.replace(second=0, microsecond=0)
rowid=[]
stmt = session.prepare('SELECT * FROM schedules WHERE source=? AND type= ? AND scheduled_for = ?')
schedule_remove_stmt = session.prepare("DELETE FROM schedules WHERE source = ? AND type = ? AND scheduled_for = ? AND id = ?")
schedule_insert_stmt = session.prepare("INSERT INTO schedules(source, type, scheduled_for, id) VALUES (?, ?, ?, ?)")
schedules_to_delete = []
articles={}
source=''
type=''
try:
    rows = session.execute(stmt, [source,type, scheduled_for])
    article_schedule_delete = ''
    for row in rows:
        schedules_to_delete.append({'id':row.id,'scheduled_for':row.scheduled_for})
        article_schedule_delete=article_schedule_delete+'\''+row.id+'\','
        rowid.append(row.id)
    article_schedule_delete = article_schedule_delete[0:-1]
    cql = 'SELECT * FROM articles WHERE id in (%s)' % article_schedule_delete
    articles_row = session.execute(cql)
    for row in articles_row:
        articles[row.id]=row.created_at
except Exception as e:
    print e
    log.info('select error is:%s' % e)
try:
    for row in schedules_to_delete:
        batch = BatchStatement()
        batch.add(schedule_remove_stmt, (source, type, row['scheduled_for'],row['id']))
        try:
            if row['id'] in articles.keys():
                next_schedule =d
                elapsed = datetime.utcnow() - articles[row['id']]
                if elapsed <= timedelta(hours=1):
                    next_schedule += timedelta(minutes=6)
                elif elapsed <= timedelta(hours=3):
                    next_schedule += timedelta(minutes=18)
                elif elapsed <= timedelta(hours=6):
                    next_schedule += timedelta(minutes=36)
                elif elapsed <= timedelta(hours=12):
                    next_schedule += timedelta(minutes=72)
                elif elapsed <= timedelta(days=1):
                    next_schedule += timedelta(minutes=144)
                elif elapsed <= timedelta(days=3):
                    next_schedule += timedelta(minutes=432)
                elif elapsed <= timedelta(days=30) :
                    next_schedule += timedelta(minutes=1440)
                if not next_schedule==d:
                    batch.add(schedule_insert_stmt, (source,type, next_schedule.replace(second=0, microsecond=0),row['id']))
                    #log.info('schedule id:%s' % row['id'])
        except Exception as e:
            print 'key error:',e
            log.info('HOW IT CHANGES %s %s %s %s ERROR:%s' % (source,type, next_schedule.replace(second=0, microsecond=0), row['id'],e))
        session.execute(batch,30)
except Exception as e:
    print 'schedules error is =======================>',e
    log.info('schedules error is:%s' % e)

非常感谢帮助，我真的不知道如何解决这个问题！

Answer 1

我认为在这种情况下你不应该使用批处理语句，因为你想要使用批处理为不同的分区键执行大量操作，这会导致超时异常。您应该使用批处理来保持表同步，但不能用于性能优化。您可以在this article

中找到有关滥用批次的详情

使用asynchronous driver api更适合为您执行大量删除查询。它将允许保持代码的性能并避免协调器过载。

Cassandra集群中的操作超时错误

1 个答案: